Supply air system

ABSTRACT

An apparatus and a method for controlling the same for conditioning an air flow for an industrial installation, the apparatus having a cooling medium circuit, a cooler incorporated into the cooling medium circuit and having a cooling medium inlet and a cooling medium outlet, at least one consumer incorporated into the cooling medium circuit and having a cooling medium inlet and a cooling medium outlet, a supply air device for conditioning air for the industrial installation, wherein the supply air device has an air/cooling medium heat exchanger, an air inlet for feeding air outside the industrial installation to the air/cooling medium heat exchanger, an air outlet for feeding air from the air/cooling medium heat exchanger to the industrial installation, a cooling medium inlet and a cooling medium outlet.

RELATED APPLICATION

The present application claims priority to German Application No. 102015 016 330.2 filed Dec. 17, 2015—the contents of which are fullyincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus for conditioning an air flow foran industrial installation, having a cooling medium circuit, a coolerincorporated into the cooling medium circuit and having a cooling mediuminlet and a cooling medium outlet, at least one consumer incorporatedinto the cooling medium circuit and having a cooling medium inlet and acooling medium outlet, a supply air device for conditioning air for theindustrial installation, wherein the supply air device has anair/cooling medium heat exchanger, an air inlet for feeding air outsidethe processing chamber to the air/cooling medium heat exchanger, an airoutlet for feeding air from the air/cooling medium heat exchanger to theindustrial installation, a cooling medium inlet and a cooling mediumoutlet.

Moreover, the invention relates to a method for controlling an apparatusfor conditioning an air flow for an industrial installation.

2. Description of the Prior Art

Such a combination of a cooler and a supply air device is often used inindustrial installations for processing objects in a processing chamber.Such industrial installations can be a dryer, a warehouse or a coatingplant for vehicle bodies or vehicle components, for example. In theselocations, use is often made of a supply air device, which suppliesindividual sealed processing chambers or even the entire installationwith conditioned outside air, for example. In this case, conditioningrelates primarily to temperature control of the air to be supplied butalso to humidification of the air. Depending on the location of theinstallation, it is accordingly necessary to cool outside air which isat a high temperature and to heat outside air which is at a lowtemperature, for example. At temperate latitudes, this means that thesupply air device is in a cooling mode in summer and in a heating modein winter.

Both processes—cooling and heating—are associated with a correspondingenergy consumption. Depending on the design of the installation, thecooler can consume electric energy, for example, and the correspondingheating device can consume gas, for example.

To an increasing extent, consideration is being given, when designingsuch installations, not only to the one-off procurement costs but alsoto the overall energy consumption of such an installation. However, evenin the case of existing installations, there is a need to minimize theoverall energy consumption over a year of operation.

Thus, it is an object of the invention to specify an apparatus of thetype stated at the outset and a corresponding method which enableinvestment costs and/or the average overall energy consumption to bereduced.

SUMMARY OF THE INVENTION

This object may be achieved by an apparatus for conditioning an air flowfor an industrial installation, having a cooling medium circuit, acooler incorporated into the cooling medium circuit and having a coolingmedium inlet and a cooling medium outlet, at least one consumerincorporated into the cooling medium circuit and having a cooling mediuminlet and a cooling medium outlet, a supply air device for conditioningthe air flow, wherein the supply air device has an air/cooling mediumheat exchanger, an air inlet for feeding air outside the industrialinstallation to the air/cooling medium heat exchanger, an air outlet forfeeding air from the air/cooling medium heat exchanger to the industrialinstallation, a cooling medium inlet and a cooling medium outlet,wherein the cooling medium outlet of the consumer can be connected tothe cooling medium inlet of the supply air device.

The apparatus according to the invention for conditioning an air flowfor an industrial installation has a cooling medium circuit, a cooler,e.g. a refrigeration unit, incorporated into the cooling medium circuitand having a cooling medium inlet and a cooling medium outlet, at leastone consumer incorporated into the cooling medium circuit and having acooling medium inlet and a cooling medium outlet.

In the present case, an industrial installation is taken to be an areaof an industrial installation, e.g. a workshop, spray booth or dryer, tobe supplied with a conditioned, primarily temperature-controlled, airflow. This can be a space which is sealed off or can be sealed off, aspace having air locks or a space having a constant or intermittent airflow. The object may also be to supply the area with the air flow onlywhen required.

In the present case, a consumer is intended to mean a device which usesthe cooling medium cooled by the cooler, while heating said medium, i.e.consumes it, as it were, in terms of energy. This can be a matter ofindividual appliances in the installation, a group of appliances in theinstallation, a single heat exchanger or even additional areas or spacesto be conditioned in an industrial installation, such as workshops,spray booths or similar.

A plurality of consumers can be connected in parallel or in series andmay also be regarded as one consumer.

Moreover, the installation has a supply air device for conditioning airfor an industrial installation. The supply air device has an air/coolingmedium heat exchanger, an air duct with an air inlet for feeding airoutside the industrial installation, that is to say, for example,outside air, to the air/cooling medium heat exchanger, and an air outletfor feeding air from the air/cooling medium heat exchanger to theindustrial installation, and a cooling medium inlet and a cooling mediumoutlet.

According to the invention, it is envisaged that the cooling mediumoutlet of the consumer can be connected to the cooling medium inlet ofthe supply air device. Subject to certain conditions, therefore, thecooling medium consumed—i.e. heated—by the consumer can be fed to thesupply air device. In the supply air device, heat transfer from theheated cooling medium to the air flow to be fed to the industrialinstallation can take place in the air/cooling medium heat exchanger.Once the consumer has transferred sufficient thermal energy to thecooling medium, this can be used by means of the supply air device toheat the air flow to be fed to the industrial installation. This canlead to a saving of the thermal energy that has to be made available toheat the air since, to a certain extent, waste heat from the consumercan be used to heat the air.

At the same time, the release of thermal energy from the cooling mediumto the air flow brings about cooling of the cooling medium flowingthrough the supply air device. This reduces the cooling-medium coolingcapacity that has to be provided by the cooler and represents a furtherenergy saving.

In an advantageous embodiment, provision can be made for the supply airdevice to have a humidifier. Humidifying the supply air prior to heatingenables the cooling medium to be cooled adiabatically throughevaporation of the moisture supplied and thus allows a reduction in thecooling capacity that has to be provided by the cooler.

One embodiment of the installation envisages that the cooler is designedfor operation without a free cooling unit. In the present case, a freecooling unit is understood to mean a device in which the cooling mediumis cooled by air using the convection principle. A free cooling unit isgenerally situated outside a building. The air passed through the freecooling unit consists substantially of outside air and accordingly hasan outside air temperature. By means of a free cooling unit, the coolingcapacity to be provided by the cooler can be reduced since the coolingmedium is pre-cooled by the free cooling unit. By virtue of the factthat the cooling medium outlet of the consumer can be connected to thecooling medium inlet of the supply air device, the supply air device canassume the function of a free cooling unit, which may therefore beobsolete or can be given correspondingly smaller dimensions.

A particularly preferred embodiment of the installation has a controlsystem, which is designed to establish the connection between thecooling medium outlet of the consumer and the cooling medium inlet ofthe supply air device if the temperature of the air supplied via the airinlet of the supply air device is below the temperature of the coolingmedium at the cooling medium inlet of the supply air device. Thus, assoon as there is a significant temperature difference, e.g. 1.5° C.,between the air supplied via the air inlet of the supply air device—thatis to say, for example, the outside air—and the cooling mediumtemperature downstream of the consumer, the cooling medium can be cooledby means of the outside air or the air flow to be fed to the industrialinstallation can be heated.

Further embodiments of the invention are given in the dependent claims.

The object may furthermore be achieved by a method for controlling anapparatus for conditioning an air flow for an industrial installation.The apparatus comprises a cooling medium circuit having a cooler, atleast one consumer incorporated into the cooling medium circuit and asupply air device, incorporated into the cooling medium circuit, forconditioning outside air for the industrial installation. The methodcomprises the following steps: determining the temperature of theoutside air; and heating the outside air in the supply air device bymeans of the cooling medium downstream of the consumer if thetemperature of the outside air falls below a threshold temperature.Thus, as soon as the temperature of the outside air is low enough, it isheated by means of the cooling medium, or the cooling medium is cooledby the outside air. In this way, the above-explained advantages of anenergy saving in heating the outside air or in the necessary cooling ofthe cooling medium are obtained.

A development of the method envisages that the method additionallycomprises the step of determining the temperature of the cooling mediumdownstream of the consumer. The temperature of the cooling mediumdownstream of the consumer thus represents the threshold temperature.Thus, as soon as the temperature of the outside air has fallen below thetemperature of the cooling medium downstream of the consumer or there isa sufficiently large temperature difference between the twotemperatures, the outside air can be heated by means of the coolingmedium and the cooling medium can be cooled by means of the outside air.

In an advantageous development of the method, it is envisaged that theoutside air is humidified before being heated.

In a particularly preferred embodiment of the method, heating theoutside air causes cooling of the cooling medium, and the cooled coolingmedium is fed to a further consumer.

Thus, the cooling medium cooled by the supply air device can be feddirectly to a further consumer, such as a cooling zone or a spray booth.

Further embodiments of the method are given in the dependent methodclaims.

Other advantages and aspects of the present invention will becomeapparent upon reading the following description of the drawings anddetailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the invention are explained in greaterdetail below with reference to the drawings, in which:

FIG. 1 shows a schematic illustration of an apparatus according to theinvention for conditioning an air flow for an industrial installation;

FIG. 2 shows a first switching state of the apparatus in FIG. 1; and

FIG. 3 shows a second switching state of the apparatus in FIG. 1.

DESCRIPTION OF PREFERRED ILLUSTRATIVE EMBODIMENTS

While this invention is susceptible to embodiments in many differentforms, there is described in detail herein, preferred embodiments of theinvention with the understanding that the present disclosures are to beconsidered as exemplifications of the principles of the invention andare not intended to limit the broad aspects of the invention to theembodiments illustrated.

FIG. 1 shows a schematic illustration of an apparatus 10 forconditioning an air flow for an industrial installation. The industrialinstallation can form a processing chamber 11, for example, which isillustrated only schematically and can be a drying chamber, a coolingzone, a spray booth or the like, for example, or, alternatively, can beconstructed from a plurality of processing chambers.

The apparatus 10 has a cooling medium circuit 12, the flow direction ofwhich is indicated by arrows. In the present case, water is used as thecooling medium. Of course, it is also possible to use other coolingmedia.

A cooler 14, e.g. a cooling appliance, is incorporated into the coolingmedium circuit 12. The cooler 14 can be equipped, as an independentunit, with a dedicated refrigerating circuit, comprising a condenser,evaporator, compressor and expansion valve, for example. The cooler 14comprises a cooling medium inlet 141 and a cooling medium outlet 142.The cooler 14 is designed, by means of electric energy for example, tocool the cooling medium flowing into the cooling medium inlet 141 and todischarge it again in a cooled state at the cooling medium outlet 142.Possible temperatures of the cooling medium are in a range of 10-22° C.,typically 12-16° C. at the cooling medium inlet 141, and in a range of6-16° C., typically 6-10° C., at the cooling medium outlet and a typicalratio of the inlet temperature to the outlet temperature could be 12/6,15/7 or 16/10, for example.

The cooling medium circuit 12 is maintained by means of a pump 16.

Likewise incorporated into the cooling medium circuit 12 in theembodiment shown in FIG. 1 are a first consumer 18 and a second consumer20. The first and second consumers 18, 20 each have a cooling mediuminlet 181, 201 and a cooling medium outlet 182, 202. In the embodimentshown in FIG. 1, the two consumers 18, 20 are connected in parallel. Ofcourse, serial connection of the two consumers 18, 20, just one consumeror a larger number of consumers would also be conceivable.

Likewise incorporated into the cooling medium circuit 12 is a supply airdevice 22 having a cooling medium inlet 221 and a cooling medium outlet222. Moreover, the supply air device 22 has an air inlet 223 and an airoutlet 224. Via the air inlet 223, the supply air device 22 can draw inair from outside the processing chamber 11 by means of a blower 226 anddischarge it to the processing chamber 11 via the air outlet 224.Moreover, the supply air device 22 has an air/cooling medium heatexchanger 225 and, optionally, a secondary pump 227 for the coolingmedium. The air/cooling medium heat exchanger 225 is connected both tothe cooling medium circuit 12 and to the air duct feeding air to theprocessing chamber 11 and allows heat transfer from the cooling mediumto the air or vice versa, depending on the temperature conditions. Boththe cooling medium outlet 222 of the supply air device 22 and thecooling medium outlets 182, 202 of the consumers 18, 20 are connected tothe cooling medium inlet 141 of the cooler 14.

In order to adapt the installation 10 during operation to the prevailingtemperature conditions, in particular to the temperature of the air atthe air inlet 223, various control valves and lines are provided for thecooling medium. A line 24 leading from the pump 16 to the consumers 18,20 and to the supply air device 22 divides into a line 26, which extendsparallel to the consumers 18, 20, and a line 28, which supplies theconsumers 18, 20. The outlet of the consumers 18, 20 is connected to thecooling medium inlet 141 by a line 30, which extends parallel to thesupply air device 22. At the same time, the outlet of the consumers 18,20 is connected to the cooling medium inlet 221 of the supply air device22 by a line 32.

Respective control valves are arranged in lines 26, 30, 32. In the openstate, the control valve 261 arranged in line 26 makes it possible toconnect the supply air device 22 in parallel with the consumers 18, 20and thus to distribute the cooling medium delivered from the cooler 14via line 24 to the consumers 18, 20 and the supply air device 22. In theclosed state of control valve 261, the supply air device 22 can only besupplied with cooling medium via the cooling medium outlets 182, 202 ofthe consumers 18, 20 and line 32.

In the open state, the control valve 301 arranged in line 30 allows thecooling medium consumed by the consumers 18, 20 to be dischargeddirectly to the cooler 14. In the closed state of control valve 301, theconsumed cooling medium can only be delivered to the supply air device22 via line 32.

In the closed state, the control valve 321 arranged in line 32 preventsa transfer of cooling medium whose energy has not been consumed directlyinto the cooler 14 from line 26 via lines 32, 30.

Various operating states of the installation 10 will now be explainedwith reference to FIGS. 2 and 3, which show various switching states ofthe installation 10 in FIG. 1.

FIG. 2 shows a first switching state of the installation 10, in whichcontrol valves 261, 301 are open and control valve 321 is closed. Inthis switching state, the consumers 18, 20 and the supply air device 22are connected in parallel. This means that the cooling medium deliveredfrom the cooler 14 via line 24 is distributed between the supply airdevice 22 and the consumers 18, 20. The cooling medium outlets 222, 182,202 of the supply air device 22 and of the consumers 18, 20 are eachconnected by corresponding lines to the cooling medium inlet 141 of thecooler 14.

This switching state is adopted when the outside air drawn in via theair inlet 223 of the supply air device 22 has a higher temperature thanthe cooling medium at the cooling medium outlets 182, 202 of theconsumers 18, 20. In this case, it is generally indicated to cool theoutside air drawn in to a desired temperature. For this purpose, heattransfer takes place from the cooling medium flowing into theair/cooling medium heat exchanger 225 via the cooling medium inlet 221of the supply air device 22 to the outside air flowing through theair/cooling medium heat exchanger 225. In this operating state, there isno recovery of the increase in the temperature of the cooling mediumproduced by the consumers 18, 20. This mode of operation can also bereferred to as a summer operating state.

This mode of operation is generally also adopted when the temperature ofthe outside air, although above the return temperature of the coolingmedium, is still so low that it does not yet require cooling but mayeven require heating.

FIG. 3 shows a second switching state of the installation 10, in whichthe control valves 261, 301 are closed and control valve 321 is open.The consumers 18, 20, on the one hand, and the supply air device 22, onthe other hand, are now in a serial configuration. The cooling mediumdelivered by the pump 16 via line 24 first of all flows through theconsumers 18, 20, where it undergoes a temperature increase. The coolingmedium leaving the cooling medium outlets 182, 202 passes via line 32 tothe cooling medium inlet 221 of the supply air device 22 and then flowsthrough the air/cooling medium heat exchanger 225. There, the heatedcooling medium can release thermal energy to the air which is drawn invia the air inlet 223 and is discharged, for example, to the processingchamber 11 via the air outlet 224. Since the pressure drop across theoverall system is increased in the case of serial connection of theconsumers 18, 20, on the one hand, and of the supply air device 22, onthe other hand, the secondary pump 227 can be switched on in this caseor can operate with an increased volume flow and/or delivery pressure.This compensation allows a constant effective total pressure drop acrossthe consumers and the supply air device.

This operating state is chosen if the temperature of the air which isdrawn in via the air inlet 223—that is to say, in this case, the outsideair—is below the temperature of the cooling medium at the cooling mediumoutlets 182, 202. The cooling medium cooled in this way can be passed toother consumers of the installation 10 in order to be used there, forexample, in a cooling zone or in a spray booth for process cooling. Asan alternative, the cooled cooling medium can be passed to the cooler14, as shown in FIG. 3, and thus reduce the energy consumption thereof.This mode of operation can also be referred to as a winter operatingstate.

If the temperature of the outside air is −9° C., for example, and thecooling medium circuit 12 is designed for a feed temperature of 10° C.in line 142 and a return temperature of 16° C. in line 141, thetemperature of the air after the air/cooling medium heat exchanger 225is 5° C. In order to bring the air to be fed to the processing chamber11 to the required temperature of 20° C., it is heated to 18° C. bymeans of an additional heating device so as to be blown into theprocessing chamber 11 by the blower 226 at 20° C. after compression. Ata typical air throughput of 86,000 m³/h, this can mean a recoveredcooling capacity of, for example, 400 kW at the air/cooling medium heatexchanger 225 and a saved heating capacity of about 400 kW at theheating device. A correspondingly smaller heating capacity of theheating device can therefore be chosen and a free cooler can bedispensed with, resulting in lower investment costs.

On the one hand, this reduces the energy consumption of the cooler 14.On the other hand, less energy or no energy has to be used to heat theair to be fed to the processing chamber 11. On the one hand, thisrenders obsolete an additional free cooling system, which is otherwiseassociated with the cooler 14, and thus reduces costs of investment intothe installation 10. On the other hand, the annual energy consumption ofthe overall installation is reduced by saving energy for heating theoutside air. At the same time, retrofitting of existing installationswith relatively little outlay is possible—essentially comprisinginstalling control valves 261, 321, 301, if appropriate a secondary pump227 and the additional line 32.

In the original design of such an installation 10, the cooling mediumcircuit overall can be designed for higher temperatures, for example.This leads to larger savings since the “winter” operating state in FIG.3 can be used in a larger proportion of the year. Moreover, it may beadvantageous to arrange the supply air device 22 in the vicinity of thecooler 14, thus enabling the entire return of the cooling medium circuit12 to be used by the supply device 22 at the highest possibletemperature. Overall, the savings effect is all the greater, the lowerthe average annual temperature of the outside air at the location wherethe installation 10 is sited.

While in the foregoing there has been set forth various embodiments ofthe invention, it is to be understood that the present invention may beembodied in other specific forms without departing from the spirit orcentral characteristics thereof. The present embodiments, therefore, areto be considered in all respects as illustrative and not restrictive,and the invention is not to be limited to the details given herein.While specific embodiments have been illustrated and described, numerousmodifications come to mind without significantly departing from thecharacteristics of the invention and the scope of protection is onlylimited by the scope of the accompanying claims.

1. An apparatus for conditioning an air flow for an industrialinstallation, comprising: a) a cooling medium circuit, b) a coolerincorporated into the cooling medium circuit and having a cooling mediuminlet and a cooling medium outlet, c) at least one consumer incorporatedinto the cooling medium circuit and having a cooling medium inlet and acooling medium outlet, d) a supply air device for conditioning the airflow, wherein the supply air device has an air/cooling medium heatexchanger, an air inlet for feeding air outside the industrialinstallation to the air/cooling medium heat exchanger, an air outlet forfeeding air from the air/cooling medium heat exchanger to the industrialinstallation, a cooling medium inlet and a cooling medium outlet,wherein e) the cooling medium outlet of the consumer can be connected tothe cooling medium inlet of the supply air device.
 2. The apparatusaccording to claim 1, wherein the supply air device has a humidifier. 3.The apparatus according to claim 1, wherein the cooler is designed foroperation without a free cooling unit.
 4. The apparatus according toclaim 1 further comprising a control system which is designed toestablish a connection between the cooling medium outlet of the consumerand the cooling medium inlet of the supply air device if the temperatureof the air supplied via the air inlet of the supply air device is belowthe temperature of the cooling medium at the cooling medium inlet of thesupply air device.
 5. A method for controlling an apparatus forconditioning an air flow for an industrial installation, wherein theapparatus comprises a cooling medium circuit having a cooler, at leastone consumer incorporated into the cooling medium circuit and a supplyair device, incorporated into the cooling medium circuit, forconditioning outside air for the industrial installation, the methodcomprising the steps of: determining the temperature of the outside air;and heating the outside air in the supply air device by means of thecooling medium downstream of the consumer if the temperature of theoutside air falls below a threshold temperature.
 6. The method accordingto claim 5, further comprising the step of: determining the temperatureof the cooling medium downstream of the consumer, wherein the thresholdtemperature is the temperature of the cooling medium downstream of theconsumer.
 7. The method according to claim 1, further comprising thestep of: comparing the outside air temperature and the cooling mediumtemperature.
 8. The method according to claim 5, further comprising thestep of: humidifying the outside air before heating the outside air. 9.The method according to claim 5, wherein heating the outside air causescooling of the cooling medium, and the cooled cooling medium is fed to afurther consumer.